Tesla Motors, Inc.

Tesla, Inc.

Francisco LePort

Scott Ira Kohn

Weston Arthur Hermann

Michael Bell

Alex Prilutsky

Orion Andrew King

A battery pack includes an enclosure containing a plurality of battery modules. A cooling system disposed among and electrically isolated from the plurality of battery modules uses a coolant solution that is a first mixture of a first liquid and a second liquid in a predetermined ratio to produce a first boiling point. Boiling of the coolant solution changes the predetermined ratio to produce a second boiling point that is higher than the first boiling point and that is sufficient to induce a thermal runaway condition for the plurality of battery module. A sensor monitors at least one operational characteristic of the plurality of battery modules and a controller determines a possible high voltage electrolysis within the enclosure based upon the at least one operational characteristic. A remediation system is responsive to the possible high voltage electrolysis to decrease risks associated with the possible high voltage electrolysis when operated.

Response to high voltage electrolysis of coolant in a battery pack

A computer-implemented method to respond to an exceptional charge event including an overdischarge in an energy storage system having a plurality of series-connected battery elements. The method includes monitoring, using the microprocessor, the energy storage system for a charge imbalance using a first detection modality; initiating a reduction of said charge imbalance using a first response modality; monitoring, using the microprocessor, the energy storage system for the overdischarge of a particular one battery element of the plurality of battery elements using a second detection modality different from said first detection modality; and initiating a response to said exceptional charge event using a second response modality different from said first response modality, said response decreasing a risk associated with said overdischarge.

Response to detection of an overdischarge event in a series connected battery element

An apparatus and method providing for detecting and responding to high voltage electrolysis within an electric vehicle battery enclosure to limit possible excessive thermal condition of the individual battery cells and modules. A microprocessor-implemented response system for high voltage electrolysis in a battery pack an evaluator to monitor, using the microprocessor, a high voltage electrolysis flag indicative of a possible high voltage electrolysis within an enclosure including a plurality of electrically-coupled battery modules storing energy for the battery pack and a coolant distribution system disposed among and electrically isolated from the plurality of battery modules; and a remediation system, coupled to the enclosure and responsive to the possible high voltage electrolysis when the evaluator detects a likelihood of the possible high voltage electrolysis, to decrease risks associated with the possible high voltage electrolysis when operated.

A battery cell design is disclosed that provides a predictable pathway through a portion of the cell (e.g., the cell cap assembly) for the efficient release of the thermal energy that occurs during thermal runaway, thereby reducing the chances of a rupture in an undesirable location. Furthermore the disclosed design maintains the functionality of the cell cap as the positive terminal of the cell, thereby having minimal impact on the manufacturability of the cell as well as its use in a variety of applications.

Battery cap assembly with high efficiency vent

A system and method for identifying and responding to exceptional charge events of series-connected energy storage elements.

Transient detection of an exceptional charge event in a series connected battery element

A system and method for identifying and responding to exceptional charge events of series-connected energy storage elements can include: a first charge imbalance detection system monitoring, using the microprocessor, the energy storage system for a charge imbalance using a first detection modality, said first charge imbalance detection system initiating a reduction of said charge imbalance using a first response modality; a second charge imbalance detection system monitoring, using the microprocessor, the energy storage system for an exceptional charge event of a particular one battery element of the plurality of battery elements using a second detection modality different from said first detection modality; and a remediation system initiating a response to said exceptional charge event using a second response modality different from said first response modality, said response decreasing a risk associated with said exceptional charge event.

Response to detection of an overcharge event in a series connected battery element

A system and method for identifying and responding to exceptional charge events of series-connected energy storage elements. An exceptional charge event detector for an energy storage system having a plurality of series-connected battery elements, comprising: a data acquisition system determining, for each battery element of the plurality of series-connected battery elements, a series of charge dependent parameters during an operational period of the energy storage system; a controller, coupled to said data acquisition system, establishing a characterization for each battery element of the plurality of series-connected battery elements from said series of charge dependent parameters; wherein said characterization includes either a normal characteristic pattern or an exceptional characteristic pattern for each time segment of a plurality of time segments spanning said operational period; and wherein said controller detects an exceptional charge event for a selected one battery element whenever said characterization for said selected one battery element includes an exceptional characteristic pattern in any particular time segment where a normal characteristic pattern is expected.

Steady state detection of an exceptional charge event in a series connected battery element

A system for detecting thermal events, e.g., thermal runaway, within a sealed battery pack based on a characterization of monitored pressure variations within the pack is provided. The system includes at least one pressure sensor coupled to the battery pack and to a pressure monitoring system that outputs pressure data representative of the battery pack pressure over time; a system controller that analyzes the pressure data and outputs a control signal when the pressure data fits a specific curve shape; and a thermal event response subsystem that performs a preset response upon receipt of the control signal from the system controller. The system may include a secondary effect monitoring system, wherein the thermal event response subsystem performs the preset response when the pressure data fits a specific curve shape and the secondary effect is detected by the secondary effect monitoring system.

Battery pack pressure monitoring system for thermal event detection

An electric circuit, including an electric load operable from an operating current; an energy storage system providing the operating current at both a first mode and a second mode with the first mode having a first current in a first range of zero to a first particular current value and with the second mode having a second current in a second range of the first particular current value to a second particular current value; and an active protection coupled to the energy storage system, the active protection dynamically reconfigurable between a first mode and a second mode, the first mode applying a first overcurrent protection rating to the operating current when the operating current is operating in the first mode and the second mode applying a second overcurrent protection rating to the operating current when the operating current is operating in the second mode.

Dynamic current protection in energy distribution systems

An apparatus and method providing for detecting and responding to high voltage electrolysis within an electric vehicle battery enclosure to limit possible excessive thermal condition of the battery cells and modules. The present invention includes embodiments directed towards detection algorithms and apparatus for promoting the use of voltage, current, humidity, temperature, and pressure sensors for the purpose of detecting high voltage electrolysis. Additionally, the present invention includes response processes and structures to address high-voltage electrolysis.

Detection of high voltage electrolysis of coolant in a battery pack

A method for detecting and responding to a battery thermal event within a sealed battery pack is provided. The method includes the steps of monitoring and characterizing the pressure within the battery pack over time, where identifying a battery thermal event is based on the pressure data fitting a specific curve shape, and performing a preset response when a battery thermal event is identified. The method may additionally monitor for a secondary effect associated with the battery thermal event.

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San Francisco, CA, United States of America

Francisco LePort